Both caterpillar attack and the application of caterpillar oral secretions (OS) to wounded plants triggers volatile emission. Volicitin (N-(17-hydroxylinolenoyl)-L-glutamine), present in beet armyworm (BAW, Spodoptera exigua) OS, is a powerful elicitor of volatiles in corn (Zea mays)seedlings. Following plant perception of insect attack, jasmonic acid and ethylene function as key signals in the initiation of insect-induced volatile emission and attraction of natural enemies. We further examine the role of ethylene in insect-induced volatile emission by altering the plant access to nitrogen. Nitrogen availability is known to strongly regulate ethylene sensitivity in corn seedlings. Nitrogen-induced changes in ethylene sensitivity greatly influence patterns of induced jasmonic acid accumulation and subsequent plant volatile responses to volicitin. The enhanced volatile responses and differential signaling in nitrogen deficient plants will be discussed in a mechanistic and ecological context.
Species 1: Lepidoptera Noctuidae Spodoptera exigua (beet armyworm)
Species 2: Graminaceae Poaceae Zea mays (corn)
Keywords: volicitin, volatile emissions
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